package chapter_3;


public class Test19 {
    public static void main(String[] args) {

        String str ="ab";
        str = str +"cd";
        StringBuffer sb = new StringBuffer("ab");
        StringBuffer append = sb.append("cd").append("aa").append("aa");
        String string = append.toString();
        StringBuffer reverse = append.reverse();
        System.out.println(reverse);
        StringBuilder sb2 = new StringBuilder("ab");
        sb2.append("cd");
    }
}
